-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KLWX 061127 AAA
AFDLWX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
627 AM EST THU MAR 6 2014

.SYNOPSIS...
-- Changed Discussion --
CANADIAN HIGH PRESSURE WILL BUILD SOUTHWARD INTO THE REGION TODAY.
LOW PRESSURE WILL PASS BY TO THE SOUTH AND EAST FRIDAY BEFORE HIGH
PRESSURE BRIEFLY RETURNS SATURDAY. A COLD FRONT WILL PASS THROUGH
THE REGION SATURDAY NIGHT AND HIGH PRESSURE WILL RETURN FOR EARLY
NEXT WEEK.
-- End Changed Discussion --

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
UPDATED SCA LOGISTICS FOR THE EXPIRED PORTIONS FROM EARLIER.

PREV DISC...
TRAPPED LOW LEVEL MOISTURE WILL BE THE MAIN FEATURE OF TODAY`S WX
ACROSS THE AREA. EVIDENCE OF THIS ALREADY IN THE OVERNIGHT POCKET
OF MID LEVEL CLOUDS THAT DEVELOPED LATE LAST NIGHT OVER THE NRN
HALF OF THE CWA. A STRONG 1040MB SFC HIGH DRIFTING INTO NEW
ENGLAND CONTINUES TO SPILL COLD AIR DOWN THE ERN SEABOARD OF THE
NORTHEAST DOWN INTO THE MID ATLC. SOME OF THE OVERNIGHT TEMPS WE
SAW YESTERDAY IN THE MID-TEENS STILL HANGING AROUND NORTH OF THE
MASON-DIXON LINE...WHILE MUCH OF OUR AREA HOVERING RIGHT AROUND OR
BELOW FREEZING. PART OF OUR RELATIVELY WARMER TEMPS IS THE
INSULATING EFFECT OF THE CLOUD DECK THAT WAS FAIRLY SOLID
EARLIER...NOW BREAKING UP IN RECENT HRS.

THE FRICTION EFFECT OF THE STRONG HIGH TO OUR NORTH AND AN A WEAK
OFFSHORE LOW HELPING TO STRENGTHEN THE SFC PRES GRADIENT OVER THE
ATLC AND JUST ONSHORE. THAT IS WHY THERE IS A STIFF BREEZE OVER THE
I-95 CORRIDOR AND EAST. NOT MUCH WILL CHANGE INTO THE REST OF THE
MORNING OTHER THAN A MORE EASTERLY COMPONENT THAT WILL HELP
GRADUALLY INCREASE THE SFC DEWPOINTS. HEADING INTO THE AFTN HRS...WE
WON`T GET NEARLY AS WARM AS YESTERDAY...BARELY TOPPING THE FREEZING
MARK THIS AFTN AS SKIES BOUNCE BACK-FORTH BETWEEN PARTLY/MOSTLY
CLOUDY. WENT W/ A MET/EURO BLEND FOR HIGHS.

AFTER DAYTIME HIGHS ONLY IN THE L-M30S...SFC TEMPS WON`T HAVE MUCH
TROUBLE DROPPING BACK BELOW FREEZING AND STAYING THERE AS LIGHT
PRECIP BEGINS TO APPROACH FROM THE SOUTH. YET ANOTHER COASTAL SYSTEM
LOOKS TO AT LEAST SCRAPE THE SOUTHERN PORTION OF THE CWA AS WE HEAD
INTO THE OVERNIGHT HRS TONIGHT. THE SYSTEM WILL HAVE ITS ROOTING IN
AN ANOMALOUSLY COLD CUT-OFF UPPER LOW DRIFTING OVER THE DEEP SOUTH
OVER THE COURSE OF TODAY...MAKING A PIVOT TOWARD THE NE AS THE
COASTAL LOW PRES SYSTEM QUICKLY DEVELOPS LATE TONIGHT INTO EARLY
FRI. THE PRECIP SHIELD ON THE NORTH-END OF SYSTEM WILL BEGIN TO JOG
UP THE ERN SEABOARD LATE THIS EVE AND ON OUR DOORSTEP BEFORE THE
PREDAWN HRS FRI.

THE LOW LEVEL PROFILE SHOULD BE NEAR OR ALL BELOW FREEZING OVER THE
SRN TIER OF THE CWA...W/ THE WARM NOSE JUST POKING ABOVE FREEZING IN
SPOTS FOR BRIEF PERIODS OF THE INITIAL BANDS OF INCOMING PRECIP.
THIS LOOKS TO GIVE THE SRN TIER COUNTIES THE POTENTIAL FOR A WINTRY
MIX OVERNIGHT AND INTO EARLY FRI...BETTER SNOW POTENTIAL BACK TOWARD
THE BLUE RIDGE AND WEST...BUT SOME LIGHT -RA/FREEZING DRIZZLE AND
SLEET A POSSIBILITY W/ ANY BATCH OF FALLING PRECIP.
-- End Changed Discussion --

&&

.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
CUTOFF LOW PRESSURE IN THE SOUTHERN STREAM OF THE JET WILL MOVE UP
THE MID-ATLANTIC COAST FRIDAY BEFORE MOVING OUT TO SEA FRIDAY NIGHT.
HIGH PRESSURE WILL REMAIN OVER NEW ENGLAND...ALLOWING FOR A
NORTHEAST FLOW TO CONTINUE DURING THIS TIME. THERE IS STILL SOME
UNCERTAINTY AS TO HOW FAR NORTH THE LOW WILL MAKE IT...BUT THE
LATEST TREND IN THE GUIDANCE HAS THE LOW TRACKING FARTHER NORTH UP
THE COAST BEFORE MOVING OUT TO SEA. THIS INCREASES THE CHANCES FOR
PRECIPITATION ACROSS OUR AREA FRIDAY INTO FRIDAY EVENING. THERE WILL
BE ENOUGH COLD AIR FOR WINTRY PRECIPITATION FRIDAY MORNING...WITH
THE BEST CHANCE OCCURRING ACROSS CENTRAL VIRGINIA AND SOUTHERN
MARYLAND. EVEN THOUGH THE MAIN PRECIP SHIELD WILL LIKELY REMAIN
ACROSS CENTRAL VIRGINIA AND SOUTHERN MARYLAND FRIDAY
MORNING...LOCATIONS FARTHER NORTH MAY HAVE SOME FREEZING DRIZZLE OR
FLURRIES THANKS TO LOW-LEVEL MOISTURE BEING TRAPPED UNDERNEATH THE
SUBSIDENCE INVERSION. AS OF NOW...IT APPEARS THAT ANY SNOW/SLEET
ACCUMULATIONS WOULD BE LIGHT. HOWEVER...LIGHT ICE ACCUMULATIONS FROM
FREEZING RAIN/FREEZING DRIZZLE ARE POSSIBLE AND THIS MAY HAVE A MORE
SIGNIFICANT IMPACT THE MORNING RUSH.

MILDER AIR SHOULD BE DRAWN IN OFF THE ATLANTIC OCEAN FRIDAY
AFTERNOON...ALLOWING FOR SURFACE TEMPS TO RISE ABOVE FREEZING.
HOWEVER...PLENTY OF CLOUDS ARE EXPECTED AND RAIN WILL CONTINUE TO
OVERSPREAD THE VIRGINIA PIEDMONT AND SOUTHERN MARYLAND...POSSIBLY
MAKING IT INTO THE WASHINGTON AND BALTIMORE METROPOLITAN AREAS AS
WELL. HAVE BUMPED UP POPS DUE TO THE LATEST TREND IN GUIDANCE. RAIN
MAY MIX WITH SNOW AT TIMES...ESPECIALLY IN THE BLUE RIDGE MOUNTAINS
FRIDAY AFTERNOON.

THE LOW WILL MOVE OUT TO SEA AND HIGH PRESSURE WILL BUILD OVERHEAD
FRIDAY NIGHT. RAIN ACROSS SOUTHERN MARYLAND THE VIRGINIA PIEDMONT
SHOULD END FRIDAY EVENING. CLEARING SKIES AND CHILLY CONDITIONS ARE
EXPECTED WITH MIN TEMPS DROPPING INTO THE MID TO UPPER 20S ACROSS
MOST LOCATIONS. PATCHY FOG IS POSSIBLE...ESPECIALLY IN AREAS THAT
RECEIVE PRECIPITATION DURING THE DAY FRIDAY.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE WILL BUILD OVER THE GULF COAST STATES SATURDAY WHILE A
COLD FRONT APPROACHES FROM THE NORTHWEST. A DOWNSLOPING WESTERLY
FLOW IS EXPECTED AHEAD OF THE FRONT...AND WITH SOME SUNSHINE IT WILL
TURN OUT TO BE NOTICEABLY MILDER COMPARED TO RECENT DAYS. THE COLD
FRONT WILL PASS THROUGH SATURDAY NIGHT AND SEASONABLY CHILLY
CONDITIONS ARE EXPECTED SUNDAY. HOWEVER...IT WILL NOT BE NEARLY AS
COLD AS IT HAS BEEN RECENTLY.

HIGH PRESSURE WILL ONCE AGAIN BUILD OVER THE GULF COAST STATES EARLY
NEXT WEEK WHILE A COLD FRONT APPROACHES FROM THE NORTH AND WEST.
MORE DOWNSLOPING WESTERLY WINDS ARE EXPECTED ALONG WITH SOME
SUNSHINE. THIS WILL ALLOW FOR MILD CONDITIONS. THE COLD FRONT WILL
PASS THROUGH DURING THE MIDDLE PORTION OF THE WEEK AND LOW PRESSURE
ALONG THE BOUNDARY MAY IMPACT THE WEATHER DURING THIS TIME.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
THE EARLIER SHIELD OF 5-6KFT STRATUS LAID OUT OVER MD/NRN VA HAS
BROKEN-UP SUBSTANTIALLY AND WILL CONTINUE TO DETERIORATE. IT WILL BE
REPLACED HOWEVER W/ OTHER LOW-MID DECKS AS WE HEAD INTO THE DAYTIME
HRS. THE LIGHT BUT STEADY NLY WIND WILL CONTINUE THROUGHOUT THE
DAY...STAYING IN THE 10-15KT RANGE FOR MUCH OF THE DAYTIME
HRS...DROPPING TO A 5-10KT BREEZE LATER THIS EVE. SOLID MVFR CIGS
WILL FILL-IN LATE TONIGHT AND SOME LOW-END MVFR CIGS WILL ARRIVE
TOWARD DAYBREAK AS A COASTAL LOW PRESSURE SYSTEM APPROACHES FROM THE
SOUTH. VERY LIGHT PRECIP WILL DRIFT NWD TOWARD THE AREA LATE
TONIGHT...W/ POCKETS OF WINTRY PRECIP THAT MAY INCH THEIR WAY TOWARD
THE DC METRO AREA TAF SITES AND MORE LIKELY OVER N CNTRL VA (KCHO).

LOW PRESSURE WILL TRACK UP THE MID-ATLANTIC COAST FRIDAY BEFORE
MOVING OUT TO SEA FRIDAY NIGHT. SUBVFR CONDITIONS ARE EXPECTED
FROM LOW CLOUDS. A LIGHT WINTRY MIX IS POSSIBLE FRIDAY MORNING
BEFORE PRECIPITATION CHANGES OVER TO RAIN FRIDAY AFTERNOON. HIGH
PRESSURE WILL BUILD IN BEHIND THIS SYSTEM FRIDAY NIGHT...BUT
PATCHY FOG IS POSSIBLE INTO EARLY SATURDAY MORNING.

VFR CONDITIONS ARE EXPECTED SATURDAY WITH A WESTERLY FLOW. A COLD
FRONT WILL PASS THROUGH SATURDAY NIGHT AND HIGH PRESSURE WILL BRING
MORE VFR CONDITIONS SUNDAY INTO EARLY NEXT WEEK.

&&

.MARINE...
THE COMBINATION OF A WEAK OFFSHORE LOW AND THE APPROACH OF THE
CANADIAN HIGH WILL KEEP THE BREEZY SCA WINDS OVER THE WATERS FOR
MUCH OF THE DAY...THOUGH BETWEEN NOW AND MID MRNG WILL BE THE
STRONGER BREEZES. THE GUSTIER WINDS WILL THEN SLIDE SWD OVER THE
LOWER MD BAY THIS EVE AND INTO EARLY FRI.

LOW PRESSURE WILL MOVE UP THE MID-ATLANTIC COAST FRIDAY BEFORE
MOVING OUT TO SEA FRIDAY NIGHT. A SMALL CRAFT ADVISORY IS IN EFFECT
FOR PORTIONS OF THE WATERS FRIDAY AND IT MAY NEED TO BE EXTENDED FOR
FRIDAY NIGHT INTO SATURDAY.

A WEAK COLD FRONT WILL PASS THROUGH THE WATERS SATURDAY NIGHT AND
HIGH PRESSURE WILL RETURN FOR SUNDAY INTO EARLY NEXT WEEK.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
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DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 AM EST THIS MORNING FOR ANZ530-
     531-538-539.
     SMALL CRAFT ADVISORY UNTIL 6 PM EST FRIDAY FOR ANZ532>534-537-
     540>543.
-- End Changed Discussion --

&&

$$
SYNOPSIS...BJL
NEAR TERM...GMS
SHORT TERM...BJL
LONG TERM...BJL
AVIATION...BJL/GMS
MARINE...BJL/GMS